BULLETIN  OF  THE  NEW  YORK  MINERALOGICAL  CLUB 


No.  3 


The  Minerals  of  Broadway 

New  York  Citv 


By  JAMES  G.  MANCHESTER 


NEW  YORK 
PUBLISHED    BY  THE 
MAY  1914 


CLUB 


The  New  York  Mineralogical  Club 


ORGANIZED  1886 


Officers  1914*1915 

PRESIDENT 

JAMES  Q.  MANCHESTER 


VICE-PRESIDENT 

GEORGE  E.  ASHBY 

SECRETARY  TREASURER 

WALLACE  GOOLD  LEVISON  OILMAN  S.  STANTON 

1435  Pacific  St.,  Brooklyn  402  West  153rd  St.,  Manhattan 


lEx  ICtbrtB 


SEYMOUR  DURST 


When  you  leave,  please  leave  this  book 

Because  it  has  been  said 
"  Ever'tbinQ  comes  t'  bim  wbo  waits 

Except  a  loaned  book." 


Avery  Architectural  and  Fine  Arts  Library 
Gift  of  Seymour  B.  Durst  Old  York  Library 


Bull.  No.  3,  N.  Y.  Min.  Club. 


Plate  I. 


BULLETIN 

OF  THE 

NEW  YORK  MINERALOGICAL  CLUB 


Vol.  I  MAY,    1914  No.  3 


THE  MINERALS  OF  BROADWAY,  NEW  YORK  CITY. 

By  James  G.  Manchester. 

Read  at  the  regular  meeting  of  the  New  York  Mineralogical  Club  at  the 
American  Museum  of  Natural  History,  May  t'4,  1913.  Illustrated 
with  lantern  slides  and  specimens. 

Broadway,  stretching  the  full  length  of  Manhattan  Island, 
a  distance  of  about  thirteen  miles,  has  been  called  the  greatest 
street  in  the  world.  Its  association  Avith  the  ancient  history 
of  the  city,  its  present  activities  in  business  and  amusement 
enterprises,  its  "Great  White  Way,"  the  skyscrapers  at  its 
southerly  end  and  the  miles  of  ai)artnient  houses  at  its  northerly 
end,  all  help  to  make  it  the  most  talked  of  street  in  the  world. 

The  trail  of  Broadway  over  the  island  begins  at  Bowling 
Green  and  runs  in  a  straight  line  to  Tenth  Street,  Avhere  it 
commences  to  bear  off  to  the  west,  crossing  Fifth,  Sixth  and 
Seventh  Avenues  before  it  reaches  Fift3T-ninth  Street,  there 
crossing  Eighth  Avenue.  From  this  point  to  the  north  it  was 
formerly  known  as  the  Boulevard.  Broadway  is  the  only  old 
street  in  this  part  of  the  city,  and  makes  a  break  in  the 
monotonous  regularity  of  the  rectangular  street  plan.  It  con- 
tinues its  westward  trend  until  West  End,  or  Eleventh  Avenue, 
is  reached  at  107th  Street,  where  it  again  assumes  a  straight 
course  to  170th  Street.  From  here  it  takes  up  the  old  Kings- 
bridge  Road  to  the  end  of  the  island  at  Spuyten  Duyvil  Creek. 

25 


26 


Bulletin  New  York  Mincralogical  Club. 


Broadway  has  been  a  field  for  active  mineral  collectors  for 
years.  The  many  excavations  in  the  rocks  bordering  upon  that 
highway  have  produced  minerals  of  unusual  rarity  and  beauty. 
It  is  safe  to  say  that  no  other  public  thoroughfare  can  equal 
it  in  the  variety  of  minerals  found  along  its  borders. 

Its  rock  formation  is  of  metamorphie  origin — that  is,  upon 
the  original  bed  or  foundation  of  the  Island  various  sediments 
were  deposited  which  were  later  upturned  and  contorted, 
through  the  agencies  of  pressure,  crust  movement  and  chemical 
action;  during  this  upturning  there  was  more  or  less  heat, 
either  from  the  earth's  interior  or  from  the  friction  produced  by 
vast  movements,  and  we  have  an  island  of  rock  known  as  gneiss, 
or  schist,  named  Manhattan  schist  by  local  geologists.  As  these 
deposits  Avere  upturned,  seams  and  fissures  were  left  which 
were  later  filled  with  the  minerals,  quartz,  mica,  feldspar,  etc., 
making  what  are  known  as  granite  or  pegniatic  veins  or  dikes. 
It  is  these  veins  or  dikes  Avhere  the  various  minerals  have  been 
crystallized  that  are  the  searching  points  for  the  collector. 

The  lower  end  of  Broadway  from  Twenty-third  Street  south, 
is  underlaid  by  the  same  kind  of  rock  as  is  found  in  the  upper 
end,  but  is  covered  with  clay,  sand  and  gravel  of  varying  depths. 
Even  before  this  section  of  the  island  was  covered  with  build- 
ings the  opportunity  for  collecting  minerals  was  very  remote 
and  confined  to  boulders  transported  from  localities  to  the  north 
and  west. 

A  glance  at  the  sketch  outlining  the  rock  basement  of  Broad- 
wav  from  the  Battery  to  Thirtv-third  Street,  drawn  by  William 
Herbert  Hobbs,1  shows  the  impossibility  of  collecting  minerals 
in  this  section  of  Broadway  with  such  a  depth  of  sand  and 
gravel  covering  the  bed  rock,  in  some  places  as  much  as  183  feet, 
which  is  the  case  at  Daane  Street.  The  rock  cores  of  drills 
used  in  making  tests  for  foundations  are  the  only  specimens 
procurable,  and  these  art1  good  only  for  geological  study. 

At  University  and  Washington  Heights  and  at  other  points 


1  United  States  Geological  Survey,  Bull.  270. 


Manchester,  The  Minerals  of  Broadway. 


27 


to  the  north,  where  the  rock  rises  above  or  is  just  below  the 
surface,  opportunity  is  given  the  collector  to  search  for  min- 
erals. 

The  crystalline  limestones  extending  from  Vermont  to 
North  Carolina  come  to  the  surface  at  the  extreme  northerlv 
end  of  the  Island  and  Broadway  cuts  through  this  deposit.  The 
outcropping  of  this  limestone  is  quite  noticeable  to  the  traveler 
in  the  Broadway  subwav,  for  soon  after  the  train  emerges  from 
the  tunnel  at  Fort  George  and  comes  out  into  the  open  at 
Dyckman  Street,  the  passenger's  eye  is  attracted  by  the  glisten- 
ing crystalline  limestone  to  the  left  of  the  track.  This  locality, 
known  as  Tnwood  Valley,  lias  produced  some  fine  minerals,  but 
the  field  of  research  is  rapidly  being  curtailed  by  the  big  apart- 
ment structures. 

The  rocks  and  minerals  of  Manhattan  Island  have  been 
written  about  for  nearly  a  hundred  years,  or  to  be  more  exact, 
the  first  record  we  have  of  New  York  City  as  a  mineral  locality 
is  a  list  of  minerals  published  in  the  Mineralogical  Journal  in 
the  vear  1814.  In  1825  "A  Catalogue  of  American  Minerals" 
was  published  by  Samuel  Robinson,  M.D.,  and  the  minerals  of 
Xew  York  County  were  prominently  mentioned.  In  1865  Dr. 
H.  Credner,  the  German  geologist,  thought  the  rocks  hereabouts 
to  be  of  so  much  interest  that  he  published  in  Germany  a  paper 
"On  the  Geology  of  the  Vicinity  of  Xew  York  City." 

These  writers  have  been  followed  by  many  others,  among 
them  Berkey,  Cozzens,  Dana,  Gale,  Gratacap,  Hobbs,  Julien, 
Kemp,  Levison,  Merrill,  Moses,  Newbury,  Xewland,  Russell, 
Stevens  and  Whitlock.  Then  again  Ave  have  had  the  splendid 
results  of  such  investigators  and  field  workers  as  Ashbv,  Bailev, 
Braun,  Camp,  Chamberlin,  Deems,  Friedrich,  Hawkins,  Hidden, 
Kunz,  Martin,  Niven,  Schernikow,  Stanton,  and  many  others 
who  are  members  of  this  Club. 

The  New  York  Mineralogical  Club  has  been  in  existence  for 
twenty-seven  years,  and  was  organized  for  the  purpose  of  devel- 
oping and  maintaining  an  interest  in  the  minerals  of  Manhat- 
tan Island.    During  this  time  many  papers  have  been  read  and 


28 


Bulletin  Xczv  York  Mineralogical  Club. 


discussions  held,  but  with  the  exception  of  a  few  scattered  re- 
gions in  the  Washington  Heights  and  Fort  George  sections  of 
the  island,  they  were  mostly  relating  to  localities  south  of  135th 
Street,  where  building  activity  was  formerly  most  prevalent. 
The  activity  in  building  operations  on  the  west  side  of  the 
Island  above  135th  Street,  resulting  from  the  construction  of 


Fig.  1.    Semi-Precious  Stones.  (Actual  Size) 

Cut  from  material  found  in  the  rocks  of  Broadway. 

A-G,  Smoky  Quartz.  L-AI,  Golden  Beryl. 

H-K.  Aquamarine  Beryl.  N-O.  Brown  Tourmaline. 

the  Broadway  subway,  has  recently  opened  up  new  localities  for 
those  interested  in  the  study  of  mineralogy  in  the  field. 

The  collecting  within  the  last  few  years  of  much  interesting 
material,  which  came  under  my  own  observation,  was  thought 
to  be  of  sufficient  importance  to  be  recorded  in  the  proceedings 
of  this  Club,  thereby  putting  into  permanent  shape  additional 
data  relating  to  the  mineralogical  history  of  the  Island. 

It  has  been  my  good  fortune  to  have  resided  in  that  section 
of  Manhattan  Island  known  as  Washington  Heights,  where  con- 
siderable excavation  has  been  in  progress.  While  the  excavat- 
ing required  for  the  erection  of  buildings  is  only  superficial, 


Manchester,  The  Minerals  of  Broadway. 


29 


and  does  not  go  deep  into  the  bed  rock,  nevertheless,  the  field 
collector  who  is  systematic  in  his  work  will  be  fully  repaid  for 
his  labor.  The  rapidity  with  which  the  rock  is  removed  after 
blasting  makes  it  difficult  for  the  material  to  be  properly  ex- 
amined and  no  doubt  many  line  specimens  are  lost. 

The  subject  of  this  paper  has  made  it  necessary  to  rely  upon 
several  publications  for  data  relating  to  minerals  collected 
years  ago  in  that  section  of  Broadwav  lying  south  of  West 
135th  Street.  The  publications  referred  to  are  the  "Geology  of 
the  City  of  New  York,"  by  L.  P.  Gratacap,  A.M. ;  "The  Minerals 
of  New  York  County,"  by  B.  B.  Chamberlm,"  and  the  New  York 
State  Museum  Bulletin  No.  70,  "List  of  New  York  Mineral 
Localities,"  by  H.  P.  Whitlock,  C.E.  The  published  lists  of 
minerals  collected  on  Manhattan  Island  in  many  instances  fail 
to  <>ive  the  exact  localitv,  and  in  referring  to  these  records  onlv 
those  minerals  that  are  listed  as  beinc,  found  on  Broadwav,  or 
in  the  block  contiguous  to  that  thoroughfare,  are  herein  noted. 
For  the  more  recent  finds  in  the  Washington  Heights  and 
Inwood  section  of  Broadway  the  cross-town  streets  are  given  in 
order  to  record  the  exact  locality  (  Plate  II).  With  but  few 
exceptions  the  minerals  noted  were  found  in  crystallized  con- 
dition. 

AMPHIBOLE  (Tremolite) 

At  I'OTth  Street  and  Broadwav  there  were  found  several 
deposits  of  tremolite  embedded  in  the  limestone.  Tremolite  is  a 
variety  of  amphibole,  having  usually  a  white  to  gray  color,  and 
occurring  in  fibrous  or  columnar  masses,  with  a  somewhat  silky 
lustre.  It  takes  its  name  from  Tremola  Valley  in  the  Alps, 
where  this  mineral  was  first  discovered. 

AMPHIBOLE  (Asbestus) 

Tremolite  and  other  varieties  of  amphibole,  except  those  con- 
taining much  alumina,  pass  into  fibrous  varieties,  the  fibers  of 
which  are  sometimes  very  long,  fine,  flexible,  and  easily  separa- 
ble by  the  Aimers,  and  look  like  flax.    These  kinds  are  called 


30 


Bulletin  New  York  Mineralogical  Club. 


asbestus  (from  the  Greek  for  incombustible).  Mountain 
leather,  a  variety  of  asbestus  in  thin  flexible  sheets,  made  of 
interlaced  fibers,  was  collected  at  the  207th  Street  locality. 

AMPHIBOLE  (Byssolite) 

Byssolite,  a  green  moss-like  variety  of  amphibole,  was  found 
years  ago  at  Broadway  and  Fifty-fifth  Street,  associated  Avith 
epidote. 

APATITE 

Dark  green  crystals  of  apatite  have  been  collected  at  135th, 
162nd  and  161th  Streets  and  Broadway.  Apatite  crystals  are 
easily  broken  in  being  taken  out  of  the  Manhattan  rocks,  and 
for  this  reason  they  adorn  but  few  cabinets. 

Apatite  means  in  Greek,  "to  deceive,'-  as  this  mineral  is  often 
mistaken  for  other  species. 


BERYL 


Crystals  of  green  and  yellow  beryl  have  been  found  on 
Broadway  from  time  to  time.    Mr.  Gilman  S.  Stanton  reports 

specimens  of  green  beryl,  col- 
lected at  the  Sixtv-fifth  Street 
locality,  the  most  recent  discov- 
ery of  this  mineral  being  made 
in  several  excavations  along  Broad- 
way from  150th  Street  to  163rd 
Street.    At  15Ttli  Street  the  rock 

"  i  link  it 

was  penetrated  by  a  pegmatite  dike 
and  several  large  green  beryl  crys- 
tals were  taken  out,  one  specimen 
having  a  fine  basal  termination 
(Plate  I,  Fig.  A).  Another  speci- 
men contained  a  section  of  fine 
transparent  light  green  beryl  of  the 


Fig.  2.  Golden  Beryl. 


(Magnified  2J/2  diameters.) 

aquamarine  variety.  A  visit  to  the  lapidary  resulted  in  the 
acquisition  of  several  gem  aquamarines  (Fig.  1,  H  to  K)  ;  the 


Manchester,  The  Minerals  of  Broadway. 


31 


largest  stone,  weighing  about  1V2  carats,  is  of  a  pale  green 
color  and  is  an  unusually  handsome  stone,  both  in  color  and 
in  lustre,  making  it  without  doubt  the  finest  gem  stone  yet 
found  in  the  Manhattan  rocks.  Years  ago  the  dark  green 
beryls  found  on  the  Island  were  in  mistake  called  emeralds, 
which  are  a  variety  of  beryl,  and  the  early  writers  on  mineral- 
oo-y  listed  Manhattan  Island  as  one  of  the  three  localities  in 
the  United  States  where  emeralds  were  found.1 

During  the  excavating  for  an  apartment  building  just  west 
of  the  Chapel  of  the  Intercession,  Broadway  and  158th  Street, 
a  single  crystal  of  golden  beryl  was  taken  out.  The  crystal  is 
transparent  and  gems  of  a  good  color  have  been  cut  from  it  (Fig. 
1,  L-M). 

A  unique  and  rather  interesting  specimen  found  at  Broad- 
way and  207th  Street,  is  a  light  colored  yellow  beryl  crystal 
penetrating  a  crystal  of  calcite  (  Fig.  2).  The  associated  min- 
erals are  quartz  and  muscovite. 

CALCITE 

Although  calcite  crystals  are  the  commonest  of  all  kinds  of 
crystals  and  have  been  noted  in  hundreds  of  different  forms, 
they  are  quite  rare  on  Manhattan  Island.  One  might  naturally 
expect  many  crystals  to  be  in  evidence  in  the  Inwood  lime- 
stone as  they  have  been  found  quite  plentifully  in  the  limestone 
in  the  Bronx.  In  the  collection  of  New  York  City  minerals 
in  the  Hall  of  Mineralogy  at  the  American  Museum  of  Natural 
History,  there  is  but  one  specimen  of  calcite  exhibited,  and 
that  a  simple  rhombohedron  cleavage.  During  the  winter  of 
1912-1913,  at  207th  Street  and  Broadway,  there  were  found  in 
the  limestone  several  quite  transparent  calcite  crystals  of  a 
brownish  color.  These  crystals,  having  been  subjected  to  more 
or  less  Aveathering,  are  slightly  altered,  but  there  is  sufficient 
evidence  to  show  that  at  one  time  thev  had  been  crystals  of  the 
scalenohedron  habit.  At  218th  Street  and  Broadway  several 
groups  of  very  small  transparent  crystals  of  calcite  were 
found. 


1  The  Minerals  of  New  York  County,  by  B.  B.  Chamrerlix. 


32 


Bulletin  New  York  Mineralogical  Club. 


C  HA  LOOP  Y  RITE   AND  MALACHITE 


Of  the  copper  ores  Broadway  has  furnished  several  speci- 
mens of  chalcopyrite  crystals  found  in  the  Manhattan  schist  at 
170th  Street.  Thin  flakes  of  malachite  were  also  noted  at  this 
same  locality,  doubtless  a  derivative  from  the  chalcopyrite. 


In  the  block  bounded  bv  Broadway,  St.  Nicholas  Avenue, 
164th  and  165th  Streets,  there  was  found  a  small  crystal  of 
chrvsobervl  embedded  in  Manhattan  schist.  The  crystal  is 
transparent  and  of  gem  quality.  It  is  exceedingly  interesting 
from  the  crystallographers  point  of  view  in  that  two  neAv 
planes  for  the  chrvsobervl  were  noted  by  H.  P.  Whitlock,  State 
Mineralogist,  and  described1  by  him  as  follows: 

"The  crystal,  which  is  shown  in  Fiff.  3,  measures  5  mm  bv 
8  mm,  is  light  vcIIoan  ish  green  in  color  and  is  so  embedded  that 
about  one-half  of  the  prismatic  zone  is  exposed.  On  the  partly 
exposed  end  traces  of  terminating  planes  Avere  noted,  but  these 


observed.  The  planes  were  narrow  and  t  yielded  a  fair,  and  g  a 
rather  poor  reflection  of  the  goniometer  signal.  The  forms 
were  identified  from  the  folloAving  measurements  which  in  every 
case  except  that  of  m  corresponded  to  a  single  observation ;  m 
furnished  two  readings: 

*N.  Y.  State  Museum,  Bull.  158.  1911;  185. 


CHRYSOBEPvYL 


Fig.  3.  Chrysoberyl. 


Avere  so  rough  and  indefinite  that 
no  terminating  forms  could  be 
identified.  Measurements  in  the 
prismatic  zone  shoAved  the  presence 
of  the  folloAving  forms:  a (100), 
b  ( 010 ) ,  t*  (11.3.0  ) ,  m  ( 110 ) ,  s  ( 120 ) , 
r/*(370)  and  r(130).  Of  these,  t 
and  g  are  new  to  the  species.  OAving 
to  the  position  of  the  matrix  sur- 
rounding the  crystal,  only  one  face 
of  each  of  these  iicav  forms  could  be 


Manchester ,  The  Minerals  of  Broadway.  33 


LETTER 

AXGLE 

MEASTJ 

RED 

CALCULATED 

a  :  t 

100  :  11.3.0 

7° 

21' 

7° 

18*' 

:  m 

:  110 

25 

12 

25 

104 

:  ^ 

:  120 

43 

17 

43 

13* 

•  a 

•  6 

:370 

47 

15 

47 

39* 

:  r 

:  130 

54 

44 

54 

39i 

:  b 

:010 

90 

2 

90 

0 

DUMORTIERITE 

Mr.  Frederick  Braim  reports  dumortierite,  a  basic  alumin- 
ium silicate,  as  having"  been  found  at  171st  Street  and  the 
Boulevard  (Broadway).1  This  is  an  unusual  mineral  and  is 
found  in  few  localities.  When  first  discovered  on  Manhattan 
Island  it  was  thought  to  be  indicolite,  the  blue  variety  of  tour- 
maline.  but  it  was  later  identified  as  dumortierite  by  E.  S.  Dana. 
It  has  been  sparingly  found  on  the  Island  in  acicular  crystals 
of  a  beautiful  ultramarine  blue  color,  aggregated  in  fasces  or 
tufts  resembling  clippings  of  hair.2  The  mineral  occurs  almost 
entirely  in  the  feldspar,  and  rarely  in  distinct  crystals. 

EPIDOTE 

While  very  fine  specimens  of  epidote  have  been  found  on  the 
Island  thus  far  the  writer  has  obtained  but  one  specimen,  and 
that  a  verv  small  one,  from  136th  Street  and  Broadwav,  a  block 
away  from  the  famous  epidote  locality  no  longer  available  at 
Amsterdam  Avenue  and  135th  Street.  The  crystal  is  sharp 
with  brilliantly  reflecting  faces;  it  has  been  broken  and  the 
intervening  space  filled  with  quartz.  Epidote  has  also  been 
found  on  Broadwav  at  Fiftv-fifth  and  138th  Streets. 

e.  ft/ 


dumortierite.  by  W.  T.  Schaller,  U.  S.  Geo.  Survey.  Bull.  262:91. 
2  The  Minerals  of  New  York  County,  by  B.  B.  Chamberlix. 


34 


Bulletin  New  York  Mineralogical  Club. 


FLUORITE 

Mr.  H.  S.  Williams,  a  member  of  this  Club,  found  a  large 
greenish  block  of  fluorite  (six  inches  by  three)  on  Broadway, 
between  Fifty-third  and  Fifty-fourth  Streets,  during  the  ex- 
cavating for  the  subway,  and  it  is  probably  the  only  specimen 
of  this  mineral  yet  found  on  Manhattan  Island. 

GARNET 

Garnets  are  quite  a  common  mineral  on  the  Island.  They 
are  usually  opaque  and  of  a  dark  red  color  and  rarely,  if  ever, 
of  a  gem  quality.  Fine  crystals  of  this  mineral  have  been  found 
along  Broadway  from  157th  to  168th  Streets  (Fig.  4).  A 


Fig.  4.  Garnet.  (2/3  Size.) 


deposit  of  small  garnets  in  a  cream-colored  schist  was  found 
manv  years  ago  at  Broadwav  and  Twentv-third  Street.  During 
the  excavating  for  the  new  McAlpin  Hotel,  Broadway  and 
Thirty-fourth  Street,  the  neAvspapers  reported  a  find  of  garnets 
by  the  workmen.    The  rock  core  of  a  test  drill  used  on  the  site 


Manchester,  The  Minerals  of  Broadzuay. 


35 


of  the  old  Mutual  Life  Building,  at  the  southeast  corner  of 
Broadway  and  Liberty  Street,  showed  the  presence  of  garnets 
in  the  schist  at  a  point  73  feet  below  the  curb  line.  The  best 
find  of  garnets  on  the  Island  was  made  in  1888  by  Gilman  S. 
Stanton,  then  a  young  student  in  mineralogy,  who  discovered  a 
vein  at  Broadwav  and  Sixtv-fifth  Street.  Here  is  Stanton's 
description1  written  at  that  time: 

"This  vein  contained  a  remarkable  quantity  of  interesting, 
beautiful  and  exceedingly  perfect  crystals  of  garnet.  The  vein, 
which  Avas  of  coarse  granite,  cut  a  light  colored  gneiss  and 
averaged  some  three  feet  in  width.  The  mica  of  the  granite  was 
muscovite,  often  in  imperfect  crystals  seven  inches  across  and 
as  much  in  thickness.    The  smoky  quartz  and  orthoclase  oc- 


Fig.  5.   Garnets — Stanton  Collection.  (1/3  Size.) 


curred  in  correspondingly  large  masses,  the  orthoclase  some- 
times being  crystallized.  Some  of  the  groups  of  garnets  are  very 
beautiful  (Fig.  5).  One  consisting  of  fifty-nine  crystals  about 
three-eighths  of  an  inch  in  diameter,  on  a  part  of  an  orthoclase 
crystal  ten  by  eight  bv  four  inches.  An  interesting  feature  of 
the  garnets  was  their  crystalline  form.    They  were  the  com- 


1  Trans.  N.  Y.  Academy  of  Sciences,  Jan.  5,  1891,  Vol.  X  :50. 


36 


Bulletin  New  York  Mineralogical  Club. 


bination  of  the  trapezoliedron  truncating  the  rhombic  dodeca- 
hedron, the  faces  of  each  being  about  equally  prominent." 

This  deposit  was  afterwards  "discovered"  by  a  dealer  in  min- 
erals, who,  in  a  few  hours  with  men  and  tools,  took  out  all  the 
available  supply  of  garnets,  which  netted  him  a  handsome 
profit.  This  is  probably  the  only  mineral  deposit  on  the  Island 
that  has  been  worked  from  a  commercial  standpoint. 

The  most  interesting  crvstal  of  garnet  found  on  Manhattan 
Island  is  owned  by  Dr.  George  F.  Kunz,  and  at  present  forms  a 
part  of  his  loan  exhibit  of  local  minerals  in  the  NeAv  York 
Mineralogical  Club  Collection  at  the  American  Museum  of 
Natural  History.  The  following  is  a  description1  of  this  garnet 
written  by  Dr.  Kunz  : 

"The  finest  large  garnet  crystal  ever  found,  perhaps,  in  the 
United  states,  was  discovered,  strange  though  it  may  seem,  in 
the  midst  of  the  solidly-built  portion  of  New  York  City.    It  Avas 

brought  to  light  by  a  laborer 
excavating  for  a  sewer  in 
A  Vest  Thirty-fifth  Street,  be- 
tween Broadwav  and  Sev- 
enth  Avenue,  in  August, 
1885.  A  quartzite  vein,  tra- 
versing the  gneiss,  contained 
the  crvstal. 

"In  form  the  crystal  is  a 
combination  of  the  2-2  te- 
tragonal  trisoctahedron 
(trapezoliedron),  the  pre- 
dominating  form,   and    I — 

Fig.  6.    Garnet— Kunz  Collection.         dodecahedron,       and  3-3/2 

(1/3  Size.)  hexoctahedron. 

"It  weighs  nine  pounds  ten  ounces  (4.4  kilos),  and  measures 
fifteen  cm.  (six  inches)  in  its  greatest  diameter,  and  six  cm.  on 
its  largest  trapezohedral  face. 

"Twenty  of  the  trapezohedral  faces  of  the  crystal  are  perfect, 

1  Trans.  N.  Y.  Academy  of  Sciences.  May  31.  1886,  Vol.  V  :265. 

i 


Manchester,  The  Minerals  of  Broadivay. 


37 


while  the  remaining  faces  were  obliterated  in  the  formation  of 
the  crystal  by  pressure  against  the  qnartzite  matrix. 

"On  the  surface  the  color  is  a  reddish-brown,  with  an  occa- 
sional small  patch  of  what  is  apparently  chlorite,  which  greatly 
enhances  its  beauty.  On  a  fractured  surface,  however,  the 
color  is  a  light  almandine  and  the  material  in  the  interior  of 
the  crystal  is  found  to  be  very  compact." 

The  laborer  who  dug  out  this  specimen  took  it  to  a  store  in 
West  Thirty-fifth  Street  and  for  several  months  it  was  used  as 
a  door-stop.  Someone  suggested  that  it  was  a  garnet  and  a 
valuable  gem,  and  it  eventually  came  into  the  possession  of  the 
present  owner.  While  it  is  not  of  gem  quality  nevertheless  it 
is  a  remarkable  specimen.  The  accompanying  illustration 
(Fig.  (J),  from  an  engraving  by  Mr.  B.  B.  Chamberlin,  is  a 
faithful  representation  of  this  garnet.  When  we  consider  the 
difficulty  in  removing  srarnet  crystals  without  fracture  from 
the  Manhattan  rocks  we  cannot  help  but  admire  this  specimen, 
almost  perfect,  with  its  sharp  angles  and  smooth  faces. 

GRAPHITE 

Graphite  is  quite  a  rare  mineral  on  Manhattan  Island  and 
has  been  found  in  but  few  localities.  During  the  winter  of 
1912-1913  graphite  as  scale-like  inclusions  in  a  crystal  of  quartz 
was  found  at  207th  Street  and  Broadway. 

GYPSUM 

With  the  presence  of  pyrite  and  pyrrhotite  in  the  limestone 
at  the  upper  end  of  Broadway  it  is  quite  natural  that  gypsum 
should  be  in  evidence.  When  pyrite  or  pyrrhotite  is  in  the 
weathering  belt  oxidation  takes  place  and  the  action  of  the 
resulting  sulphuric  acid  on  the  limestone  forms  gypsum.  Sev- 
eral specimens  of  gypsum  in  the  shape  of  a  network  of  crystals 
deposited  on  the  gneiss  were  found  at  207th  and  218th  Streets 
and  Broadway. 


38 


Bulletin  New  York  Mineralogical  Club. 


KAOLIN 


Kaolin,  a  mineral  resulting  from  the  decomposition  of  feld- 
spar, was  reported  by  Mr.  F.  A.  Camp  as  having  been  taken  out 
at  a  point  56  feet  below  the  curl)  line  on  West  32nd  Street, 
between  Broadway  and  Fifth  Avenue.1  This  mineral  has  also 
been  found  at  Broadway  and  158th  Street. 

MAGNETITE 

During  the  Summer  of  1912,  176th  Street  was  worked  to 
grade.  In  blasting  away  the  rock  a  well  developed  vein  of  mag- 
netite in  the  Man- 
hattan schist  Avas 
brought  to  view  a 
few  feet  east  of 
Broadway.  Large 
m  a  s  s  i  v  e  speci- 
mens of  the  min- 
e  r  a  1  were  re- 
moved. A  pecu- 
liarity of  this  de- 
posit  was  that 
the  magnetite 
showed  the  cleav- 
age   lines  quite 

fig.  /.    Magnetite.  (5/6  Size.)       i   •   i  i  'j-i 

plainly,  and  with 
the  aid  of  a  light  hammer  and  chisel  the  mineral  could  be 
trimmed  so  as  to  produce  unusually  fine  pseudo-crystals 
(Fig.  7).  Magnetite  also  has  been  found  at  161th  Street  and 
Broadway.  Chamberlin  reports  magnetite  as  being  found  in 
solid  black  cubical  blocks  at  170th  Street  and  Eleventh  Avenue, 
now  Broadway  at  that  point. 

MANGANESE  OXIDES 

(Wad,  Bog-manganese,  Psilomelane,  etc.) 
Mr.  YeshiKan  has  taken  some  pains  to  examine  black,  bnrnt- 


1  Geology  of  the  City  of  New  York,  by  L.  P.  Gratacap,  A.M.,  1909:137. 


Manchester,  The  Minerals  of  Broadway. 


39 


looking-  exposures  of  the  schist,  especially  on  Washington 
Heights  at  146th  Street,  between  Broadway  and  Amsterdam 
Avenue.  These  he  found  to  be  unquestionably  accumulations 
and  crusts  of  manganese  oxides.1 

MARCASITE 

Marcasite,  a  sulphide  of  iron,  in  the  form  of  slender  capil- 
lary crystals  interwoven  like  a  wad  of  hair,  was  collected  at 
Broadway  and  207th  Street.  The  specimen  is  very  small,  and 
was  only  brought  to  view  by  dissolving  out  a  calcite  vein  in 
the  schist.  In  this  same  vein  were  minute  crystals  of  quartz, 
muscovite  and  rutile. 

MICA 

A  common  mineral  upon  the  Island  and  one  that  is  most 
noticeable  is  mica.  Mica  is  one  of  the  principal  rock-forming 
minerals  and  is  readily  distinguished  bv  its  glistening  scalelike 
coating  upon  the  rocks.  Mica  is  not  only  of  great  importance 
as  a  rock-forming  mineral  but  owing  to  its  easy  cleavage  into 
thin  plates  or  leaves  with  smooth  and  bright  surfaces,  often 
transparent,  highly  resistant  to  electricity,  and  to  both  high 
temperatures  and  sudden  changes  of  temperature,  it  also  finds 
many  applications  in  the  industrial  arts.  On  account  of  its 
possession  of  such  properties  it  has  long  been  used  for  windows 
of  stoves  and  lanterns  and  the  chimneys  of  lamps  and  gas 
burners.  A  short  time  ago  the  writer  found  a  stove-dealer  on 
Amsterdam  Avenue  at  work  splitting  books  of  mica  and  cutting 
the  sheets  into  sizes  suitable  for  the  windows  of  stove  doors. 
Upon  inquiry  it  was  found  that  he  had  secured  a  supply  of  the 
material  from  an  excavation  on  Broadway. 

Of  the  micas  the  most  common  variety  met  with  is  musco- 
vite,  a  potassium  mica.  The  mineral  gets  its  name  from  the 
fact  that  thin  transparent  sheets  were  formerly  used  in  Russia 
for  window  panes  and  was  known  as  "Muscovy  glass."  The 


1  Geology  of  the  City  of  New  York,  by  L.  P.  Gratacap,  A.M.,  1909:138. 


40 


Bulletin  New  York  Miner alogical  Club. 


name  muscovite  was  given  it  by  J.  D.  Dana  in  1850.  Masses 
of  small  crystals  of  muscovite  have  been  taken  out  at  Sixty- 
third  Street  and  Broadway.  Fine  crystals  have  been  collected 
in  excavations  from  162nd  to  170th  Streets  on  Broadway  ( Fig. 
8).  Pale  green  transparent  crystals  were  found  in  the  Inwood 
limestone  at  207th  and  218th  Streets.  At  these  same  localities 
mica  has  been  found  containing  many  inclusions  of  other  min- 
erals, such  as  green  beryl,  flattened  garnets,  finely  terminated 


Fig.  8.    Muscovite.  (1/3  Size.) 


black  tourmaline,  magnetite  in  crystals  and  in  dendritic  forms, 
crystals  of  pyrite,  pyrrhotite,  goethite,  rutile,  and  Alms  of 
quartz.  The  study  of  this  feature  of  the  mica  alone  is  an  almost 
endless  task  and  is  receiving  serious  attention  on  the  part  of 
several  members  of  this  Club,  and  we  mav  look  for  some  inter- 
esting  data  in  the  near  future. 

A  variety  of  mica  known  as  phlogopite,  or  magnesia  mica, 
contains  the  elements  magnesium  and  fluorine  in  addition  to 
those  present  in  muscovite.  It  much  resembles  muscovite  in 
appearance,  but  is  often  of  a  yellowish  or  brownish  color.  It 
differs  also  in  its  mode  of  occurrence,  being  usually  found  in 
crystalline  limestones.  Phlogopite  is  found  in  small  scalelike 
deposits  in  the  limestones  at  the  upper  end  of  Broadway,  and 


Manchester 


The 


Minerals  of  Broadway. 


41 


is  observed  in  thin  bandlike  aggregates  running  through  the 
limestone,  often  associated  with  pyrite. 

Another  variety  of  mica  found  at  162nd  Street  and  Broad- 
way is  biotite.  This  differs  from  phlogopite  in  containing  some 
iron  in  addition  to  magnesium:  it  is  consequently  darker  in 
color,  being  deep  brown  or  black.  The  mineral  takes  its  name 
from  the  celebrated  French  physicist  and  astronomer,  J.  B.  Biot. 

MTCROLITE 

Microlite,  a  calcium  pyrotantalate,  whose  crystals  are  very 
small  and  sometimes  highly  modified,  was  found  by  W.  E. 
Hidden,  at  Thirty-ninth  Street  and  Broadway,  in  small  octahe- 
drons in  oligoclase. 

OLIGOCLxlSE 

Oligoclase,  a  mineral  of  the  feldspar  group,  has  been  found 
in  many  localities  on  the  Island.    Several  specimens  of  this 


Fig.  9.  Oligoclase.  (1/2  Size.) 


mineral  were  taken  out  of  the  schist  at  Broadway  and  161st 
Street.  The  largest  crystal  (  Fig.  9  i  measures  i):!4  inches  by 
lVo  inches,  is  greenish  gray  in  color,  and  is  remarkably  well 
developed  for  such  a  large  crystal,  the  proportion  of  the  various 


42 


Bulletin  New  York  Mineralogical  Club. 


planes  being  almost  diagrammatic ;  the  crystal  is  somewhat 
flattened  parallel  to  the  0  plane  in  which  respect  it  resembles 
those  from  Fine,  N.  Y.,  which  are  figured  by  Penfield  in  the 
Dana  System.  Crystals  of  this  mineral  were  also  found  at 
158th  and  176th  Streets  and  Broadway.  Mr.  F.  A.  Camp  re- 
ports large  crystals  of  oligoclase  collected  on  Broadway  in  the 
Washington  Heights  section. 

OPAL  (Hyalite) 

Hyalite,  a  variety  of  opal,  was  found  by  Mr.  Oilman  S. 
Stanton  in  the  block  between  Sixty-fifth  and  Sixty-sixth 
Streets,  just  west  of  Broadway.  The  mineral  was  mostly 
botryoidal  in  form,  coating  what  were  probably  joint  surfaces 
of  the  schist.  Some  was  vitreous  and  nearly  transparent — the 
Muller's  glass  variety — but  the  thicker  coatings  were  opaque 
and  milky.  This  is  the  only  find  of  opal  thus  far  recorded  for 
Manhattan  Island. 

OBTHITE 

A  mineral  containing  thorium  and  other  rare  elements  is 
orthite,  a  variety  of  allanite,  found  years  ago  at  the  southeast 
corner  of  Broadway  and  Fifty-sixth  Street.  The  crystals  were 
from  2V2  to  ?>  inches  in  length,  of  a  dark  reddish  brown  color, 
looking  much  like  thin,  rusty  nails,  often  bent  and  twisted  and 
set  in  white  oligoclase,  which  was  stained  red  in  the  vicinity  of 
the  crystals. 

PYMTE 

In  the  Inwood  limestone  at  207th,  218th  and  225th  Streets 
and  Broadway,  many  crystals  of  pyrite  have  been  taken  out, 
sliOAving  such  a  variety  of  form  and  a  brillancv  of  lustre  that 
make  them  a  welcome  addition  to  any  cabinet. 

Oue  of  these  crystals  found  at  225th  Street,  just  west  of 
BroadAvav,  was  sent  to  H.  P.  Whitlock  for  study  and  has  been 
described1  by  him  as  follows: 


*N.  Y.  State  Museum.  Bull.  158.  1911:183. 


Manchester,  The  Minerals  of  Broadway. 


43 


"The  specimen  consisted  of  a  single  small  crystal  measur- 
ing 3  mm  in  diameter  and  developed  with  almost  diagrammatic 
symmetry.  The  faces  which  are 
sharp  and  brilliant  gave  excellent 
images  of  the  signal.  This  crystal, 
which  is  illustrated  in  Fig.  10, 
shows  besides  the  forms  previously 
recorded  from  the  locality  [Kings- 
bridge]  the  forms  <Z(  110),  0(520), 
?;(650),  p(221)  and  £(421),  all  of 
which  have  been  frequently  re- 
corded for  pyrite.  The  develop- 
ment of  the  zone  [210.  001]  is  spe- 
cially characteristic  of  this  crystal,  the  forms  occurring  as  fol- 
lows: (210),  (421),  (211),  (212),  (213),  (214),  (001). 

"The  forms  occurring  in  the  zone  [001.110]  are:  (001), 
(112),  (111),  (221),  (110). 

"The  forms  were  identified  by  means  of  their  zonal  positions 
as  follows : 


Fig.  10. 


Pyrite. 


LETTER 

ANGLE 

NO. 

MEASURED 

CALCULATED 

Zone 

[100 

.110] 

a  :  g 

100 

:520 

2 

21° 

39' 

21° 

48' 

:  e 

•210 

11 

26 

35 

26 

34 

:  v 

:650 

8 

39 

44 

39 

48 

Zone 

[210. 

001] 

c  :  t 

210 

421 

8 

12 

361 

12 

36 

:  n 

211 

13 

24 

3 

24 

6 

■  P 

212 

10 

41 

47 

41 

49 

:  s 

213 

6 

53 

19 

53 

18 

:  t" 

214 

6 

60 

484 

60 

48 

Zone 

[100 

111] 

a  :  n 

100 

211 

6 

35 

16 

35 

16 

•  t> 

r 

122 

5 

15 

461 

15 

47h 

44 


Bulletin  New  York  Mincralogical  Club. 


At  207th  Street  and  Broadway  an  unusually  fine  pyrite  crys- 
tal of  the  octahedral  form  was  taken  out.  The  crystal  is 
nearly  one-half  inch  in  diameter,  the  faces  of  which  are 

beautifully  etched.  At  this 
same  locality  massive  pyrite 
was  noted.  At  Thirty-second 
Street,  near  Broadway,  at  a 
deptli  of  forty-nine  feet,  Mr. 
A.  S.  Coffin  reports  that 
quartzite  was  taken  out  coat- 
ed with  pyrite. 

Bv  the  action  of  water 
containing  oxygen  and  cal- 
cium carbonate  in  solution, 
pyrite  suffers  alteration;  the 
sulphur  is  carried  away  in  so- 
lution as  gypsum  and  the 
iron  is  left  behind  as  a  ferric 
hydroxide  (limonite)  which 
preserves  the  original  form 
of  the  crystals.     We  have 

Fig.  11.   Limonite  Pseudomorph  after    thus  a  pseudomorpll  of  lilll- 
Pyrite.  (Actual  Size.)  ,  . 

onite  alter  pyrite;  that  is, 
limonite  with  the  external  form  of  a  crystal  of  pyrite.  Limonite 
pseudomorph s  after  pyrite  were  found  at  204th  Street,  east  of 
Broadway  (Fig.  11).  Mr.  George  E.  Ashby  reports  limonite 
pseudomorphs  after  pyrite  cubes  as  inclusions  in  mica  found 
on  Broadway  at  144th  and  165th  Streets;  also  ochre  pseudo- 
morphs after  pyrite  at  the  144th  Street  locality. 

ORTHOCLASE  (Adularia) 

Several  finely  terminated  crystals  of  adularia,  the  nearly 
pure  potassium  aluminium  silicate,  were  found  in  the  Inwood 
limestone  at  207th,  218th  and  225th  Streets  and  Broadway. 
Adularia  is  a  variety  of  orthoclase  and  is  named  after  Adula, 
a  mountain  group  in  the  Orisons  Alps,  where  fine  specimens 
have  been  found. 


Manchester,  The  Minerals  of  Broadway. 


45 


PYROXENE  (Malacolite) 

Pyroxene  is  essentially  a  normal  inetasilicate  of  calcium  and 
magnesium,  also  containing  iron  manganese  or  zinc  and  some- 
times small  percentages  of  potassium  and  sodium.  The  many 
yarieties  are  usually  classified  as  aluminous  and  non-aluminous. 
Malacolite,  usually  white  or  pale  green  in  color,  is  of  the  non- 
aluminous  variety.  This  variety  is  quite  common  in  the  Inwood 
limestone  Avhere  it  is  found  in  Avell  developed  and  quite  stout 
crystals,  usually  white  in  color  (Plate  I,  Fig.  B).  The  hardness 
of  malacolite  ranges  from  5  to  0  and  when  found  exposed  to  the 
weather  it  has  outlasted  the  limestone  in  which  it  was  enclosed 
and  the  crystals  are  often  protruding  from  or  lying  loose  on  the 
matrix.    Crystals  of  malacolite  are  often  bent  and  fractured 

m* 

similar  to  the  tourmalines.  Several  fine  specimens  were  col- 
lected at  the  207th  Street  locality.  Single  crystals  of  malaco- 
lite  were  found  in  the  ploughed  fields  in  the  neighborhood  of 
218th  Street. 

PYRRHOTITE 

Distinct  crystals  of  the  mineral  pyrrhotite  are  quite 
rare  in  any  locality,  but  at  Broadway  and  218th  Street 
small  perfect  hexagonal 
crystals    of    a  tabular 

m* 

habit  were  found.  When 
taken  out  the  crystals 
were  of  a  bronze-yellow 
color  and  closely  resem- 
bled phlogopite,  a  variety 
of  mica,  but  upon  ex- 
posure to  the  air  the  color 
changed  to  a  copper-red 
and  bluish  tarnish  and 
after  other  tests  it  devel-    Fig'  lz  Pyrrhotite-  19  dia-> 

oped  that  the  mineral  was  pyrrhotite  (Fig.  12).  Massive 
pyrrhotite,  associated  with  iron  pyrites,  was  also  found  at  207th 
Street  and  Broadway.    At  215th  Street  and  Broadway  this 


46 


Bulletin  New  York  Miner alogical  Club. 


mineral  was  found  as  inclusions  in  mica,  quartz,  tourmaline 
and  calcite  crystals. 

QUARTZ 

Quartz  is  the  most  abundant  and  widely  distributed  of  all 
minerals  and  it  is  quite  natural  therefore  that  it  is  a  common 
constituent  of  the  Manhattan  rocks.    Quartz,  when  perfectly 


long,  found  at  the  orthite  locality,  Broadway  and  Fifty-sixth 
Street.  At  164th  Street  there  was  found  a  rare  form  of  quartz 
crystal,  known  as  bi-pyrainidal,  or  double  six-sided  pyramid. 
The  crystal  is  one-half  inch  in  diameter  and  is  embedded  in  feld- 
spar  (Fig.  14). 

Crystals  of  quartz  are  usually  attached  at  one  end  to  the 
rocky  matrix,  but  sometimes,  especially  when  embedded  in  a 
soft  matrix  they  may  be  bounded  on  all  sides  by  crystal  faces. 
At  Broadway  and  207th  Street,  a  number  of  minute  doubly 
terminated  quartz  crystals  were  found.  These  were  secured 
by  dissolving  the  calcite  in  acid  and  in  the  residue  were  found, 
with  the  aid  of  a  magnifying  glass,  these  most  interesting  little 
specimens  which  remind  one  of  the  loose  quartz  crystals  that 
are  sometimes  found  in  the  geodes  from  the  Bad  Lands.  At 


pure,  is  quite  transparent  and  colorless, 
this  being  the  variety  known  as  rock 
crystal. 


Rock  crystal  is  frequently,  though  not 
always,  found  in  the  form  of  terminated 
crystals,  having  usually  the  shape  of  six- 
sided  prisms  terminated  at  one  or  both 
ends  by  pyramids.  Seyeral  fine  specimens 
of  these  crystals  were  collected  at  207th 
and  218th  Streets  and  Broadway  (Fig. 
13).    Many  of  the  crystals  found  at  this 


Fig.  13.  Quartz. 
(Actual  Size.) 


locality  Ayere  of  the  tapering  form,  some 
at  first  glance  suggesting  dog-tooth  calcite. 
Chamberlin  reports  terminated  crystals  of 
quartz  one  inch  in  diameter  and  two  inches 


Manchester,  The  Minerals  of  Broadway. 


47 


this  same  locality  there  were  taken  out  several  clusters  of  rock 
crystal. 

Smoky  quartz  in  small  crystals  was  found  in  21Sth  Street 
in  the  Inwood  limestone,  but  they  do  not  compare  with  the  beau- 
tiful specimens  in  the  Kunz  collection  which  were  found  during 
the  construction  of  the  Harlem  ship  canal,  a  few  blocks  north 


Fig.  14.   Quartz.  (Actual  Size.) 


of  this  locality.  The  massive  variety  of  this  mineral  is  quite 
common  among  the  rocks  of  Manhattan.  Transparent  and  flaw- 
less specimens  from  Broadway  at  160th  and  207th  Streets  have 
been  cut  into  facetted  stones  (  Fig.  1,  A  to  G). 

EIPIDOLITE    ( Clinoehlore) 

Ripidolite,  a  mineral  of  the  chlorite  family,  was  taken  out 
of  the  rock  forty-four  feet  below  the  curb  on  Thirty-second 
Street,  between  Fifth  Avenue  and  Broadway,  by  A.  S.  Coffin.1 

EUTILE 

On  Broadway,  from  201st  to  218th  Streets,  finely  terminated 
crystals  of  rutile  in  the  limestone  were  taken  out.  Hair-like 


'Geology  of  the  City  of  New  York,  by  L.  P.  Gratacap,  A.M..  1909:142. 


48 


Bulletin  New  York  Mincralogical  Club. 


crystals  of  this  mineral  sometimes  one  inch  or  more  in  length, 
extending  across  the  cavities  in  the  limestone,  were  also  noted. 
An  unusually  fine  specimen  from  the  207th  Street  locality  is  one 

containing  two  terminated  rutile 
crystals  penetrating  a  terminated 
quartz  crystal  (Fig.  15).  Kutile 
coated  with  prochlorite  was  also 
obtained  here.  Rutile  associated 
with  quartz  and  feldspar  was  found 
at  164th  Street  and  Broad wa v. 
Clusters  of  rutile  crystals  in  rhom- 
bic  arrangement  as  inclusions  in 
muscovite  were  collected  years  ago 
at  Broadway  and  Fifty-fourth  and 
Fifty-fifth  Streets. 

Fig.  15.  Rutile.    (Mag.  15  dia.) 

STILBITE 

Stilbite,  a  silicate  of  aluminium,  calcium  and  sodium  with 
some  water,  is  a  member  of  the  zeolite  group  of  minerals  and 
therefore  of  secondary  origin.  Stanton  reports  finding  stilbite 
at  Broadway  and  Sixty-sixth  Street  in  flattened  radiations  one 
and  one-half  inches  in  diameter.  It  has  been  found  sparingly 
in  other  parts  of  the  Island. 

URANINITE  (Pitchblende) 

The  radio-active  mineral,  uraninite,  one  of  the  sources  of 
radium,  was  found  years  ago  at  Broadway  and  155th  Street, 
and  is  in  the  Kunz  collection.  Uraninite  is  also  known  as  pitch- 
blende and  within  recent  years  it  has  attracted  a  great  deal  of 
attention  through  the  discovery  by  the  late  Prof,  and  Madame 
Currie,  who  succeeded  in  isolating — radium  and  polonium — two 
elements  noted  for  their  remarkable  properties.  The  amount 
of  radium  contained  in  pitchblende,  the  richest  ore  of  radium, 
is,  however,  extremely  minute.    Many  tons  of  material  have  to 

7  7c 

be  treated  by  a  long  series  of  complex  chemical  operations  to 
obtain  even  a  small  amount  of  radium  compound. 


Manchester,  The  Minerals  of  Broadway. 


49 


TOPAZ 

A  mineral  new  to  Manhattan  and  furnished  by  Broadway, 
is  topaz,  an  aluminium  fluorsilicate.  Only  two  small  specimens 
of  the  massive  variety  were  found  and  these  in  the  block  bounded 
by  Broadway,  St.  Nicholas  Avenue,  164th  and  165th  Streets. 
The  determination  was  made  bv  H.  P.  Whitlock,  the  State  min- 
eralogist  at  Albany.  There  is  no  reason  why  topaz  should  not 
be  found  in  the  veins  or  dikes  of  the  schists  of  Manhattan 
Island. 

TOURMALINE 

A  gem  stone  that  is  growing  more  popular  as  a  jewel  is  the 
tourmaline.  While  it  has  its  romances  the  same  as  other  pre- 
cious stones,  they  are  comparatively  modern.    Broadway  has 


Fig.  16.    Brown  Tourmaline.  (Actual  Size.) 


furnished  a  number  of  fine  gem  brown  tourmaline  crystals. 
Within  the  last  year  several  finely  terminated  specimens,  asso- 
ciated with  cream  colored  calcite,  making  very  attractive  cabinet 
specimens,  were  collected  at  201st,  207th,  218th  and  225th 
Streets  and  Broadway  (  Figs.  16  and  17).  Several  of  the  smaller 
crystals  have  been  cut  for  gems  (Fig.  1,  N-O).  Small  golden 
brown  and  green  tourmalines  were  also  found  at  these  localities. 
Tourmaline  is  one  of  the  most  complex  minerals  chemically. 


50  Bulletin  New  York  Mineralogical  Club. 


Ruskin  notes  this  character  of  the  tourmaline  in  his  "Ethics  of 
the  Dust."  This  book  is  a  collection  of  Ruskin's  lectures  given 
at  a  girls'  school,  and  were  not  intended  as  an  introduction  to 
mineralogy.  Their  purpose  was  to  awaken  in  the  minds  of  the 
young  girls  a  vital  interest  in  the  subject  of  their  study;  these 

lectures  also  gave  Ruskin  an  oppor- 
tunity to  use  nature's  work  in  crys- 
tallization as  an  argument  against 
sordid  living.  Here  is  what  he  says 
of  tourmaline: 

"A  little  of  everything;  there's 
always  flint  and  clay  and  magnesia 
in  it  ;  and  the  black  is  iron  accord- 
ing to  its  f ancy ;  and  there's  boracic 
acid,  if  you  know  what  that  is,  and 
if  vou  don't,  I  cannot  tell  vou  to- 
day,  and  it  doesn't  signify;  and 
there's  potash  and  soda ;  and  on  the 
whole,  the  chemistry  of  it  is  more 
like  a  mediaeval  doctor's  prescrip- 
tion than  the  making  of  a  respecta- 
ble mineral." 

Xo  doubt  it  is  this  complexity 
of  composition  which  prevents  the 
gem  tourmaline  from  being  produced  synthetically. 

Black  tourmaline,  while  never  found  of  a  gem  quality,  has 
many  interesting  features  and  is  quite  common  in  the  rocks 
along  Broadway.  Several  finely  terminated  specimens  have 
been  collected  at  161st  and  162nd  Streets  (Fig.  18).  One  of 
the  specimens  here  illustrated  shows  that  after  the  mineral  had 
crystallized  it  was  broken  by  some  eruptive  disturbance,  but 
nature  saw  to  it  that  it  Avas  neatly  repaired  by  filling  in  the 
space  with  quartz  or  other  mineral  (Fig.  19).  This  feature  is 
quite  a  common  occurrence,  and  has  been  observed  in  other 
minerals  found  on  Manhattan  Island,  such  as  beryl,  malacolite, 
epidote,  and  chrysoberyl,  the  second  specimen  of  the  latter  col- 


Fig.  17.  Gem  Brown  Tourma- 

(2/3  Size.) 


LINE. 


Manchester,  The  Minerals  of  Broadzvay. 


51 


lected  by  Wallace  Goold  Levison  affording  a  notable  example. 

Another  feature  of  the  tourmaline  is  its  crystal  form.  The 
planes  on  a  doubly  terminated  crystal  are  not  alike  either  in 
number  or  inclination.  On  one  end  there  may  be  three  planes, 
on  the  other  six  or  even  twelve.  Such  a  peculiarity  of  form  is 
possessed  by  few  minerals. 

Crystals  of  tourmaline 
behave  in  a  peculiar  man- 
ner when  they  are  subjected 
to  changes  of  temperature. 
If  a  crystal  be  warmed  it 
develops  a  charge  of  posi- 
tive electricity  at  one  of  its 
ends,  and  a  charge  of  nega- 
tive electricity  at  the  other; 
while  if  it  be  cooled  these 
charges  are  reversed.  It  was 
in  tourmaline  that  the  phe- 
nomenon of  pyroelectricity 
was  first  observed.  On  be- 
ing heated  in  peat  ashes  its    Fig  18  Black  Tourmaline.  (Actual  Size) 

attractive  power  was  first 

observed  by  the  Dutch  in  the  early  part  of  the  18th  century. 


XENOTIME 

One  of  the  rarest  and  at  the  same  time  one  of  the  most  inter- 
esting minerals  on  Manhattan  Island  is  the  mineral  xenotime. 
In  May,  1912,  at  165th  Street  and  Broadway,  while  excavation 
was  in  progress  for  the  new  Audubon  Theatre,  one  small  crystal 
of  this  mineral  was  found.  Xenotime  is  quite  interesting  in 
that  it  is  composed  of  several  rare  elements,  among  them  tho- 
rium, a  radio-active  chemical.  In  1815,  this  mineral  was  sup- 
posed by  Berzelius,  the  Swedish  chemist,  to  contain  a  new  metal, 
which  he  named  thorium,  before  the  later  thorium  was  discov- 


52  Bulletin  New  York  Mineralogical  Club. 

ered.  The  name  xenotime  refers  to  the  fact  that  the  crystals  are 
small,  not  showy,  and  were  long  unnoticed. 


Fig.  19.    Black  Tourmaline.  (2/3  Size.) 


IN  CONCLUSION 

The  foregoing  list  is  made  up  of  47  varieties,  representing 
39  distinct  species  of  minerals,  and  with  but  few  exceptions  all 
have  been  noted  by  the  writer  in  the  rocks  of  Broadway.  A 
complete  list  of  minerals  found  in  New  York  City,  as  reported 
by  Chamberlin,  consists  of  118  varieties,  or  82  species.  With 
such  a  record  one  cannot  help  feeling  that  the  collector  is  very 
fortunate  indeed  to  be  a  resident  in  a  great  metropolis  whose 
rocks  are  filled  with  such  treasures  of  the  mineral  kingdom. 
There  is  still  much  unimproved  property  in  the  northern  section 
of  the  city  awaiting  the  excavators  with  their  steam  drills  and 
derricks  to  pave  the  way  for  gigantic  structures  and  incidentally 
to  open  up  new  fields  for  research  for  the  lover  of  nature  as 
expressed  in  minerals.  However,  if  building  operations  keep  up 
their  present  pace  it  will  not  be  many  years  before  the  Island 
will  be  completely  covered  with  buildings  and  the  opportunity 
for  collecting  minerals  will  be  lost  forever.  It  therefore  devolves 
on  those  who  are  interested  to  be  ever  alert  with  a  view  to  saving 
a  beautiful  crystal  or  a  fine  gem  from  destruction. 


Bull.  No.  3 


218th  Street 
CALCITE 
GYPSUM 
PHLOGOPITE 
PYRITE 

PYROXENE — M  ALACOLITE 
PYRRHOTITE 

QUARTZ — ROCK  CRYSTAL 
RUTILE 

TOURMALINE — Brown 
TOURMA  -INE— Green 


207th  Street 
AM  PHI  BOLE — Asbestus 
AMPHIBOLE— Tremollte 
CALCITE 
GRAPHITE 
GYPSUM 
MARCASITE 
MUSCOVITE 

ORTHOCLASE— ADULARIA 
PYRITE 

PYROXENE— M  ALACOLITE 
PYRRHOTITE 

QUARTZ— ROCK  CRYSTAL 
QUARTZ — Smoky 
RUTILE 

TOURMALINE — Brown 


168th  Street 

BIOTITE 

GARNET 

Muscovite  end. 

Tourmaline 

TOURMALINE— 

Black 

162nd-163rd  Streets 
APATITE 
BERYL— Green 
GARNET 

Muscovite  enclosing  Beryl 
PYRITE 

TOURMALINE— Black 


161st-162nd  Streets 
APATITE 
BIOTITE 
GARNET 
MUSCOVITE 
OLIGOCLASE 
QUARTZ— Smoky 
TOURMALINE — Black 


158th  Street 
BERYL — Golden 
GARNET 
KAOLIN 
OLIGOCLASE 
TOURMALINE— Black 


225th  Street 
CALCITE 

ORTHOCLASE— ADULARIA 
PYRITE 

QUARTZ— ROCK  CRYSTAL 
RUTILE 

TOURMALINE— Brown 


176th  Street 
MAGNETITE 
OLIGOCLASE 
TOURMALINE — Black 


170th  Street 
CHALCOPYRITE 
GARNET 
MALACHITE 
TOURMALINE— Black 


165th-166th  Streets 
BERYL— Green 
GARNET 

Muscovite  enclosing  Pyrite 
TOURMALINE— Black 
XENOTIME 


164th-165th  Streets 
APATITE 
CHRYSOBERYL 
GARNET 
MAGNETITE 
MUSCOVITE 
QUARTZ— Bipyramidal 
RUTILE 
TOPAZ 

TOURMALINE— Black 


157th-158th  Streets 
BERYL — Aquamarine 
BERYL — Green 
GARNET 
MUSCOVITE 
PYRITE 


141st  Street 
TOURMALINE— Black 


135th-136th  Streets 
APATITE 
EPIOOTE 
GARNET 

TOURMALINE— Black 


THE  MINERALS  OF  BROADWAY 

(Washington  Heights  and  Inwood  Section) 
Collected  1909-1913  by  J.  G.  Manchester 


The  New  York  Mineralogical  Club. 


The  New  York  Mineralogical  Club  was  organized  in  October,  1886, 
but  it  was  not  until  the  eighth  meeting  that  officers  were  elected.  Those 
then  chosen  were  George  F.  Kunz,  Secretary;  B.  B.  Chamberlin, 
Treasurer ;  Daniel  S.  Martin,  Rev.  J.  Selden  Spencer,  E.  A.  Hutchins 
and  George  F.  Kunz,  Executive  Committee ;  R.  P.  Whitfield  and 
L.  P.  Gratacap,  Curators.  For  several  years  -there  was  no  President, 
the  host  of  the  evening  filling  that  office  for  the  occasion,  since  the 
meetings  were  held  at  private  houses. 

The  object  of  the  Club  is  to  develop  and  maintain  an  interest  in 
the  minerals  and  rocks  of  Manhattan  Island  through  collecting  and  the 
study  and  comparison  of  existing  collections.  The  principal  series  in 
existence  at  the  time  of  the  organization  of  the  Club  was  that  of  the 
late  Benjamin  B.  Chamberlin,  who  had  devoted  more  than  twenty 
years  to  the  study  and  to  the  collection  of  minerals  on  Manhattan 
Island.  After  the  death  of  Mr.  Chamberlin  this  collection  was 
acquired  by  the  Club,  and  it  is  now  permanently  deposited  in  the 
American  Museum  of  Natural  History.  With  this  has  been  deposited 
the  George  F.  Kunz  Collection,  besides  many  gifts  to  and  purchases  by 
the  Club,  the  whole  forming  a  nearly  complete  representation  of 
Manhattan  Island  minerals,  which  is  now  on  exhibition  in  the  Morgan 
Hall  of  Mineralogy. 

The  Club  meets  monthly,  from  October  to  May,  at  the  American 
Museum  of  Natural  History,  for  the  consideration  of  papers 
upon  mineralogical  topics.  Summer  meetings  in  the  shape  of  field 
excursions  are  made  from  time  to  time  to  nearby  points  of  interest  to 
the  collector.  Persons  interested  in  mineralogy  are  invited  to  cor- 
respond with  the  Secretary  regarding  membership  in  the  Club.  The 
Club  is  an  affiliated  society  of  the  New  York  Academy  of  Sciences. 


